Merge remote-tracking branch 'origin/RTC-Rewrite' into RTC-Rewrite

# Conflicts:
#	RelayClient/MainPage.xaml.cs

RelayClient/MainPage.xaml.cs

@@ -1,18 +1,17 @@
-using RelayClient.Crypto;
+using System.Text.Json.Serialization;
-using WebSocketSharp;
+using RelayClient.Crypto;
-using System.Text.Json;
+using RelayClient.Services;
-using System.Text.Json.Serialization;
 using RelayShared.Rtc;
 using RelayShared.Services;
 
 namespace RelayClient;
 
-
 public partial class MainPage : ContentPage
 {
     private readonly string _username;
-    private readonly WebSocket _wsc;
+    private readonly RelaySocketClient _socket;
-    private string? _serverPublicKey;
+    private readonly RtcBridgeService _rtc;
+
     private string? _currentChannelId;
     private string? _currentChannelName;
 
@@ -33,19 +32,31 @@ public partial class MainPage : ContentPage
             KeyStorage.SavePublicKey(_username, keys.publicKey);
         }
 
-        _wsc = new WebSocket("ws://localhost:1337/");
-        
-        _wsc.OnMessage += WscOnMessage;
-        _wsc.Connect();
-
-        var publicKey = KeyStorage.LoadPublicKey(_username);
-        _wsc.Send($"REGISTER_KEY|{_username}|{publicKey}");
-        _wsc.Send("GET_SERVER_KEY");
-        _wsc.Send("GET_CHANNELS");
-        
-        hybridWebView.SetInvokeJavaScriptTarget(this);
         ServerAPI.setupClient();
 
+        _socket = new RelaySocketClient(_username);
+        _rtc = new RtcBridgeService(
+            _username,
+            _socket,
+            hybridWebView,
+            () => _currentChannelId,
+            SafeSendRawToWebView
+        );
+        
+        hybridWebView.SetInvokeJavaScriptTarget(_rtc);
+
+        _socket.Log += Console.WriteLine;
+        _socket.ChannelListReceived += HandleChannelList;
+        _socket.EncryptedChatReceived += HandleEncryptedChat;
+        _socket.EncryptedRtcSignalReceived += payload =>
+        {
+            MainThread.BeginInvokeOnMainThread(async () =>
+            {
+                await _rtc.HandleIncomingRtcSignalAsync(payload);
+            });
+        };
+
+        _socket.Connect();
     }
 
     private void SendButton_OnClicked(object? sender, EventArgs e)
@@ -65,7 +76,7 @@ public partial class MainPage : ContentPage
         if (string.IsNullOrWhiteSpace(text))
             return;
 
-        if (string.IsNullOrWhiteSpace(_serverPublicKey))
+        if (string.IsNullOrWhiteSpace(_socket.ServerPublicKey))
         {
             Console.WriteLine("Server public key not loaded yet.");
             return;
@@ -77,7 +88,7 @@ public partial class MainPage : ContentPage
             return;
         }
 
-        var encrypted = E2EeHelper.EncryptForRecipient(text, _serverPublicKey);
+        var encrypted = E2EeHelper.EncryptForRecipient(text, _socket.ServerPublicKey);
 
         var payload = new SocketEncryptedMessage
         {
@@ -90,8 +101,7 @@ public partial class MainPage : ContentPage
             EncryptedKey = encrypted.EncryptedKey
         };
 
-        var json = JsonSerializer.Serialize(payload);
+        _socket.SendJson(payload);
-        _wsc.Send(json);
 
         Console.WriteLine($"[{_username}] sent encrypted message.");
 
@@ -99,34 +109,8 @@ public partial class MainPage : ContentPage
         MessageEntry.Focus();
     }
 
-    private void WscOnMessage(object? sender, MessageEventArgs e)
+    private void HandleChannelList(SocketChannelList channelList)
     {
-        if (e.Data.StartsWith("SERVER:REGISTERED_KEY:"))
-        {
-            Console.WriteLine(e.Data);
-            return;
-        }
-        
-        // SafeSendRawToWebView($"[{_username}] RAW WS DATA: {e.Data}");
-        
-        Console.WriteLine($"[{_username}] RAW WS DATA: {e.Data}");
-
-        try
-        {
-            using var doc = JsonDocument.Parse(e.Data);
-            var root = doc.RootElement;
-
-            if (!root.TryGetProperty("Type", out var typeElement))
-                return;
-
-            var type = (SignalType) typeElement.GetInt32();
-
-            if (type == SignalType.ChannelList)
-            {
-                var channelList = JsonSerializer.Deserialize<SocketChannelList>(e.Data);
-                if (channelList is null)
-                    return;
-
         _channels.Clear();
         _channels.AddRange(channelList.Channels.OrderBy(c => c.CreatedAt));
 
@@ -136,8 +120,8 @@ public partial class MainPage : ContentPage
                                  .FirstOrDefault()
                              ?? _channels.OrderBy(c => c.CreatedAt).FirstOrDefault();
 
-                if (defaultChannel is not null)
+        if (defaultChannel is null) return;
-                {
+
         _currentChannelId = defaultChannel.ChannelId;
         _currentChannelName = defaultChannel.Name;
 
@@ -145,42 +129,23 @@ public partial class MainPage : ContentPage
         {
             ChannelLabel.Text = $"#{_currentChannelName}";
             RenderChannelList();
-                        await PushRtcContextToJsAsync();
+            await _rtc.PushRtcContextToJsAsync();
         });
 
-                    _wsc.Send($"GET_HISTORY|{_username}|{_currentChannelId}");
+        _socket.SendRaw($"GET_HISTORY|{_username}|{_currentChannelId}");
     }
 
+    private void HandleEncryptedChat(SocketEncryptedMessage payload) {
+        if (payload.RecipientUsername != _username)
             return;
-            }
 
-            if (type == SignalType.ServerPublicKey)
+        string decryptedText;
+
+        try
         {
-                var serverKeyMessage = JsonSerializer.Deserialize<ServerPublicKeyMessage>(e.Data);
-                if (serverKeyMessage is not null)
-                {
-                    _serverPublicKey = serverKeyMessage.PublicKey;
-                    Console.WriteLine($"[{_username}] loaded server public key.");
-                }
-
-                return;
-            }
-            
-            if (type == SignalType.EncryptedSignal)
-            {
-                var payload = JsonSerializer.Deserialize<SocketRtcSignalMessage>(e.Data);
-                if (payload is null)
-                    return;
-
-                if (payload.ChannelId != _currentChannelId)
-                    return;
-
-                if (payload.SenderUsername == _username)
-                    return;
-
             var privateKey = KeyStorage.LoadPrivateKey(_username);
 
-                var decryptedJson = E2EeHelper.DecryptForRecipient(
+            decryptedText = E2EeHelper.DecryptForRecipient(
                 new EncryptedPayload
                 {
                     CipherText = payload.CipherText,
@@ -190,140 +155,26 @@ public partial class MainPage : ContentPage
                 },
                 privateKey
             ); 
-                
-                var rtcSignal = JsonSerializer.Deserialize<RtcSignalMessage>(decryptedJson);
-
-                if (rtcSignal is null)
-                    return;
-
-                if (!string.IsNullOrWhiteSpace(rtcSignal.To) &&
-                    !string.Equals(rtcSignal.To, _username, StringComparison.OrdinalIgnoreCase))
-                {
-                    SafeSendRawToWebView($"Ignoring RTC signal meant for {rtcSignal.To}");
-                    return;
-                }
-
-                SafeSendRawToWebView("Received encrypted RTC signal: " + decryptedJson);
-
-                MainThread.BeginInvokeOnMainThread(async () =>
-                {
-                    await SendRtcSignalToJsAsync(decryptedJson);
-                });
-
-                return;
-            }
-            
-            if (type is SignalType.OfferUpdated or SignalType.AnswerUpdated or SignalType.CandidateAdded or SignalType.CallLeft)
-            {
-                var rtcNotification = JsonSerializer.Deserialize<RtcNotificationMessage>(e.Data);
-                if (rtcNotification is null)
-                    return;
-
-                var notificationType = rtcNotification.Type;
-                var notificationChannelId = rtcNotification.ChannelId ?? string.Empty;
-
-                if (notificationChannelId != _currentChannelId)
-                    return;
-
-                // SafeSendRawToWebView("RTC notification received: " + notificationType + " for " + notificationChannelId);
-
-                MainThread.BeginInvokeOnMainThread(async () =>
-                {
-                    switch (notificationType)
-                    {
-                        case SignalType.OfferUpdated:
-                        {
-                            if (rtcNotification.Username == _username)
-                                break;
-
-                            var offer = await GetRtcOffer();
-                            await SendRtcSignalToJsAsync(offer);
-                            break;
-                        }
-                        case SignalType.AnswerUpdated:
-                        {
-                            var answer = await ServerAPI.GetAnswerForChannelAsync(_currentChannelId);
-                            if (answer is not null)
-                            {
-                                await AnswerCallback(answer);
-                            }
-                            break;
-                        }
-                        case SignalType.CandidateAdded:
-                        {
-                            if (rtcNotification.Username == _username)
-                                break;
-
-                            try
-                            {
-                                IceCandidate? iceCandidate = JsonSerializer.Deserialize<IceCandidate>(rtcNotification.Direction);
-
-                                if (iceCandidate is null)
-                                    break;
-
-                                IceCandidateCallback(iceCandidate);
         }
         catch (Exception ex)
         {
-                                SafeSendRawToWebView($"Candidate rejected: {ex.Message}");
+            Console.WriteLine($"[{_username}] failed to decrypt chat: {ex.Message}");
-                            }
-
-                            break;
-                        }
-                        case SignalType.CallLeft:
-                        {
-                            SafeSendRawToWebView("RTC call left notification received.");
-                            RtcLeaveCallback();
-                            break;
-                        }
-                    }
-                });
-
             return;
         }
 
-            if (type != SignalType.EncryptedChat)
-                return;
-
-            var pyload = JsonSerializer.Deserialize<SocketEncryptedMessage>(e.Data);
-            if (pyload is null)
-                return;
-
-            if (pyload.RecipientUsername != _username)
-                return;
-
-            Console.WriteLine($"[{_username}] received encrypted payload for {pyload.RecipientUsername}");
-
-            var privKey = KeyStorage.LoadPrivateKey(_username);
-
-            var decryptedText = E2EeHelper.DecryptForRecipient(
-                new EncryptedPayload
-                {
-                    CipherText = pyload.CipherText,
-                    Nonce = pyload.Nonce,
-                    Tag = pyload.Tag,
-                    EncryptedKey = pyload.EncryptedKey
-                },
-                privKey
-            );
-
-            Console.WriteLine($"[{_username}] decrypted message from {pyload.SenderUsername}: {decryptedText}");
-
         var message = new ChatMessage
         {
-                SenderUsername = pyload.SenderUsername,
+            SenderUsername = payload.SenderUsername,
             Text = decryptedText,
             Timestamp = DateTime.Now
         };
 
-            if (!_messagesByChannel.ContainsKey(pyload.ChannelId))
+        if (!_messagesByChannel.ContainsKey(payload.ChannelId))
-            {
+            _messagesByChannel[payload.ChannelId] = [];
-                _messagesByChannel[pyload.ChannelId] = [];
-            }
 
-            _messagesByChannel[pyload.ChannelId].Add(message);
+        _messagesByChannel[payload.ChannelId].Add(message);
 
-            if (pyload.ChannelId == _currentChannelId)
+        if (payload.ChannelId == _currentChannelId)
         {
             MainThread.BeginInvokeOnMainThread(() =>
             {
@@ -331,16 +182,10 @@ public partial class MainPage : ContentPage
             });
         }
     }
-        catch (Exception ex)
-        {
-            Console.WriteLine($"[{_username}] failed to process websocket message: {ex.Message}");
-        }
-    }
 
     protected override void OnDisappearing()
     {
-        _wsc.OnMessage -= WscOnMessage;
+        _socket.Disconnect();
-        _wsc.Close();
         base.OnDisappearing();
     }
 
@@ -364,11 +209,14 @@ public partial class MainPage : ContentPage
 
                 MainThread.BeginInvokeOnMainThread(async () =>
                 {
-                    await PushRtcContextToJsAsync();
+                    await _rtc.PushRtcContextToJsAsync();
+
                     if (channel.Type == ChannelType.Voice)
                     {
+                        if (!RtcView.IsVisible)
                             SwapView();
-                        // JoinRtcChannel(); //TODO: Join voice calls when clicking channel rather than a separate button
+
+                        _ = _rtc.JoinRtcChannel();
                     }
                 });
 
@@ -376,9 +224,7 @@ public partial class MainPage : ContentPage
                 RenderCurrentChannelMessages();
 
                 if (!_messagesByChannel.ContainsKey(channel.ChannelId))
-                {
+                    _socket.SendRaw($"GET_HISTORY|{_username}|{channel.ChannelId}");
-                    _wsc.Send($"GET_HISTORY|{_username}|{channel.ChannelId}");
-                }
             };
 
             SidebarList.Children.Add(button);
@@ -403,7 +249,7 @@ public partial class MainPage : ContentPage
 
     private async void RenderSingleMessage(ChatMessage message)
     {
-        bool isOwnMessage = message.SenderUsername == _username;
+        var isOwnMessage = message.SenderUsername == _username;
 
         var bubble = new Border
         {
@@ -438,7 +284,6 @@ public partial class MainPage : ContentPage
             MessagesScrollView.IsVisible = true;
             RtcView.IsVisible = false;
             ViewSwapped.Text = "Swap to Web View";
-
         }
         else
         {
@@ -447,254 +292,17 @@ public partial class MainPage : ContentPage
             ViewSwapped.Text = "Swap to Message View";
         }
     }
+
     private void SwapView_OnClicked(object? sender, EventArgs e)
     {
         SwapView();
     }
 
-    #region RTC Functions
-    public async Task JoinRtcChannel()
-    {
-        if (string.IsNullOrWhiteSpace(_currentChannelId))
-            return; //false;
-
-        _wsc.Send($"RTC_JOIN_CHANNEL|{_username}|{_currentChannelId}");
-
-        // SafeSendRawToWebView($"Attempting to join RTC Channel {_currentChannelName} | {_currentChannelId} ");
-
-        //bool active = await ServerAPI.GetIsChannelActiveAsync(_currentChannelId);
-
-        //SafeSendRawToWebView($"Rtc Channel {_currentChannelName} | {_currentChannelId} is active: {active}");
-
-        return; //active;
-    }
-    
-    public void LeaveRtcChannel()
-    {
-        if (string.IsNullOrWhiteSpace(_currentChannelId))
-            return;
-
-        _wsc.Send($"RTC_LEAVE_CHANNEL|{_username}|{_currentChannelId}");
-    }
-    
-    public async void WriteRtcOffer(string json)
-    {
-        try
-        {
-            RtcDescription? description = JsonSerializer.Deserialize<RtcDescription>(json);
-            DBOffer offer = new DBOffer
-            {
-                ChannelId = _currentChannelId,
-                Username = _username,
-                SessionDescription = description
-            };
-            var response = await ServerAPI.PostOfferAsync(offer);
-            SafeSendRawToWebView(response.ToString());
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView($"WriteRtcOffer failed: {ex.Message}");
-        }
-
-    }
-    public async Task<string> GetRtcOffer()
-    {
-        RtcDescription? offer = await ServerAPI.GetOffersForChannelAsync(_currentChannelId);
-        return JsonSerializer.Serialize(offer);
-    }
-    
-    public async void WriteRtcAnswer(string json)
-    {
-        // SafeSendRawToWebView("WriteRtcAnswer entered with: " + json);
-
-        try
-        {
-            RtcDescription? description = JsonSerializer.Deserialize<RtcDescription>(json);
-            DBOffer answer = new DBOffer
-            {
-                ChannelId = _currentChannelId,
-                Username = _username,
-                SessionDescription = description
-            };
-            await ServerAPI.PostAnswerAsync(answer);
-            SafeSendRawToWebView("WriteRtcAnswer posted successfully");
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("WriteRtcAnswer failed: " + ex.Message);
-        }
-    }
-
-    public async void WriteIceCandidate(string json)
-    {
-        try
-        {
-            IceCandidate? candidate = JsonSerializer.Deserialize<IceCandidate>(json);
-            DBIceCandidate DBCandidate = new DBIceCandidate
-            {
-                ChannelId = _currentChannelId,
-                Username = _username,
-                Candidate = candidate
-            };
-            if (candidate == null) return;
-            await ServerAPI.PostIceCandidateAsync(DBCandidate);
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("WriteIceCandidate failed: " + ex.Message);
-        }
-    }
-
-    public async void IceCandidateCallback(IceCandidate candidate)
-    {
-        try
-        {
-            await hybridWebView.InvokeJavaScriptAsync("IceCandidateAdded", [candidate], [HybridJSType.Default.IceCandidate]);
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("WriteIceCandidate failed: " + ex.Message);
-        }
-    }
-    public async Task AnswerCallback(RtcDescription answer)
-    {
-        answer.sdp = answer.sdp.Replace("\r\n", "(rn)");
-        try
-        {
-            await hybridWebView.InvokeJavaScriptAsync("AnswerCallbackJS", [answer], [HybridJSType.Default.RtcDescription]);
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("AnswerCallback failed: " + ex.Message);
-        }
-    }
-
-    public async void RtcLeaveCallback()
-    {
-        try
-        {
-            await hybridWebView.InvokeJavaScriptAsync("RtcLeaveCall", [], []);
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("RtcLeaveCallback failed: " + ex.Message);
-        }
-    }
-    
-    private Task SendRtcSignalToJsAsync(string rawJson)
-    {
-        MainThread.BeginInvokeOnMainThread(async () =>
-        {
-            try
-            {
-                SafeSendRawToWebView("Dispatching RTC signal to JS");
-
-                var jsArg = JsonSerializer.Serialize(rawJson);
-
-                await hybridWebView.EvaluateJavaScriptAsync(
-                    $"window.RelaySocket.receiveRtcSignal({jsArg})"
-                );
-
-                SafeSendRawToWebView("RTC signal dispatched to JS");
-            }
-            catch (Exception ex)
-            {
-                SafeSendRawToWebView("SendRtcSignalToJsAsync failed: " + ex.Message);
-            }
-        });
-
-        return Task.CompletedTask;
-    } //Remove?
-    
-    private async Task PushRtcContextToJsAsync()
-    {
-        var usernameJson = JsonSerializer.Serialize(_username);
-        var channelIdJson = JsonSerializer.Serialize(_currentChannelId);
-
-        await hybridWebView.EvaluateJavaScriptAsync($"window.setUsername({usernameJson})");
-        await hybridWebView.EvaluateJavaScriptAsync($"window.setChannelId({channelIdJson})");
-
-        Console.WriteLine($"[{_username}] pushed RTC context into HybridWebView.");
-    } //Remove?
-    
-    public void SendRtcSignal(string json)
-    {
-        SafeSendRawToWebView("SendRtcSignal entered: " + json);
-
-        if (string.IsNullOrWhiteSpace(_serverPublicKey))
-        {
-            SafeSendRawToWebView("SendRtcSignal failed: server public key not loaded.");
-            return;
-        }
-
-        RtcSignalMessage? rtcSignal;
-
-        try
-        {
-            rtcSignal = JsonSerializer.Deserialize<RtcSignalMessage>(json);
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("SendRtcSignal failed to parse RTC signal: " + ex.Message);
-            return;
-        }
-
-        if (rtcSignal is null)
-        {
-            SafeSendRawToWebView("SendRtcSignal failed: rtcSignal was null.");
-            return;
-        }
-
-        if (string.IsNullOrWhiteSpace(rtcSignal.ChannelId))
-        {
-            SafeSendRawToWebView("SendRtcSignal failed: channelId was empty.");
-            return;
-        }
-
-        try
-        {
-            var encrypted = E2EeHelper.EncryptForRecipient(json, _serverPublicKey);
-
-            var payload = new SocketRtcSignalMessage
-            {
-                Type = SignalType.EncryptedSignal,
-                SenderUsername = _username,
-                ChannelId = rtcSignal.ChannelId,
-                CipherText = encrypted.CipherText,
-                Nonce = encrypted.Nonce,
-                Tag = encrypted.Tag,
-                EncryptedKey = encrypted.EncryptedKey
-            };
-
-            var socketJson = JsonSerializer.Serialize(payload);
-            _wsc.Send(socketJson);
-
-            SafeSendRawToWebView($"SendRtcSignal sent: {rtcSignal.Type} -> {rtcSignal.ChannelId}");
-            Console.WriteLine($"[{_username}] sent RTC signal: {rtcSignal.Type} -> {rtcSignal.ChannelId}");
-        }
-        catch (Exception ex)
-        {
-            SafeSendRawToWebView("SendRtcSignal websocket/encrypt failed: " + ex.Message);
-        }
-    } //Remove?
-    
-    public async Task<string> GetRtcParticipants()
-    {
-        var participants = await ServerAPI.GetRtcParticipantsAsync(_currentChannelId);
-        return JsonSerializer.Serialize(participants);
-    }
-    
-    #endregion
-    private void OnSendMessageButtonClicked(object sender, EventArgs e)
-    {
-        SafeSendRawToWebView($"Hello from C#!");
-    }
-
     private async void OnHybridWebViewRawMessageReceived(object sender, HybridWebViewRawMessageReceivedEventArgs e)
     {
         if (e.Message == "rtc_page_ready")
         {
-            await PushRtcContextToJsAsync();
+            await _rtc.PushRtcContextToJsAsync();
             return;
         }
 
@@ -719,7 +327,7 @@ public partial class MainPage : ContentPage
     public class ChannelButton : Button
     {
         public ChannelType Type { get; set; }
-        public string Group { get; set; }
+        public string Group { get; set; } = string.Empty;
     }
 
     [JsonSourceGenerationOptions(WriteIndented = false)]
@@ -730,8 +338,5 @@ public partial class MainPage : ContentPage
     [JsonSerializable(typeof(string))]
     internal partial class HybridJSType : JsonSerializerContext
     {
-        // This type's attributes specify JSON serialization info to preserve type structure
-        // for trimmed builds.
     }
-    
 }

RelayClient/Services/RelaySocketClient.cs

@@ -0,0 +1,127 @@
+using System.Text.Json;
+using RelayClient.Crypto;
+using RelayShared.Services;
+using WebSocketSharp;
+
+namespace RelayClient.Services;
+
+public sealed class RelaySocketClient
+{
+    private readonly string _username;
+    private readonly WebSocket _socket;
+
+    public string? ServerPublicKey { get; private set; }
+
+    public event Action<string>? RawMessageReceived;
+    public event Action<SocketChannelList>? ChannelListReceived;
+    public event Action<SocketEncryptedMessage>? EncryptedChatReceived;
+    public event Action<SocketRtcSignalMessage>? EncryptedRtcSignalReceived;
+    public event Action<string>? ServerPublicKeyReceived;
+    public event Action<string>? Log;
+
+    public RelaySocketClient(string username, string url = "ws://localhost:1337/")
+    {
+        _username = username;
+        _socket = new WebSocket(url);
+        _socket.OnMessage += OnMessage;
+    }
+
+    public void Connect()
+    {
+        _socket.Connect();
+
+        var publicKey = KeyStorage.LoadPublicKey(_username);
+
+        SendRaw($"REGISTER_KEY|{_username}|{publicKey}");
+        SendRaw("GET_SERVER_KEY");
+        SendRaw("GET_CHANNELS");
+    }
+
+    public void SendRaw(string message)
+    {
+        if (_socket.ReadyState == WebSocketState.Open)
+            _socket.Send(message);
+    }
+
+    public void SendJson<T>(T payload)
+    {
+        SendRaw(JsonSerializer.Serialize(payload));
+    }
+
+    public void Disconnect()
+    {
+        _socket.OnMessage -= OnMessage;
+
+        if (_socket.ReadyState == WebSocketState.Open)
+            _socket.Close();
+    }
+
+    private void OnMessage(object? sender, MessageEventArgs e)
+    {
+        if (e.Data.StartsWith("SERVER:REGISTERED_KEY:"))
+        {
+            Log?.Invoke(e.Data);
+            return;
+        }
+
+        RawMessageReceived?.Invoke(e.Data);
+        Log?.Invoke($"[{_username}] RAW WS DATA: {e.Data}");
+
+        try
+        {
+            using var doc = JsonDocument.Parse(e.Data);
+            var root = doc.RootElement;
+
+            if (!root.TryGetProperty("Type", out var typeElement))
+                return;
+
+            var type = (SignalType)typeElement.GetInt32();
+
+            switch (type)
+            {
+                case SignalType.ChannelList:
+                {
+                    var channelList = JsonSerializer.Deserialize<SocketChannelList>(e.Data);
+                    if (channelList is not null)
+                        ChannelListReceived?.Invoke(channelList);
+
+                    return;
+                }
+
+                case SignalType.ServerPublicKey:
+                {
+                    var serverKeyMessage = JsonSerializer.Deserialize<ServerPublicKeyMessage>(e.Data);
+                    if (serverKeyMessage is not null)
+                    {
+                        ServerPublicKey = serverKeyMessage.PublicKey;
+                        ServerPublicKeyReceived?.Invoke(serverKeyMessage.PublicKey);
+                    }
+
+                    return;
+                }
+
+                case SignalType.EncryptedSignal:
+                {
+                    var payload = JsonSerializer.Deserialize<SocketRtcSignalMessage>(e.Data);
+                    if (payload is not null)
+                        EncryptedRtcSignalReceived?.Invoke(payload);
+
+                    return;
+                }
+
+                case SignalType.EncryptedChat:
+                {
+                    var payload = JsonSerializer.Deserialize<SocketEncryptedMessage>(e.Data);
+                    if (payload is not null)
+                        EncryptedChatReceived?.Invoke(payload);
+
+                    return;
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            Log?.Invoke($"[{_username}] failed to process websocket message: {ex.Message}");
+        }
+    }
+}

RelayClient/Services/RtcBridgeService.cs

@@ -0,0 +1,224 @@
+using System.Text.Json;
+using RelayClient.Crypto;
+using RelayShared.Rtc;
+using RelayShared.Services;
+
+namespace RelayClient.Services;
+
+public sealed class RtcBridgeService
+{
+    private readonly string _username;
+    private readonly RelaySocketClient _socket;
+    private readonly HybridWebView _hybridWebView;
+    private readonly Func<string?> _getCurrentChannelId;
+    private readonly Action<string> _sendRawToWebView;
+
+    public RtcBridgeService(string username, RelaySocketClient socket, HybridWebView hybridWebView,
+                            Func<string?> getCurrentChannelId, Action<string> sendRawToWebView)
+    {
+        _username = username;
+        _socket = socket;
+        _hybridWebView = hybridWebView;
+        _getCurrentChannelId = getCurrentChannelId;
+        _sendRawToWebView = sendRawToWebView;
+    }
+
+    public Task JoinRtcChannel()
+    {
+        var channelId = _getCurrentChannelId();
+
+        if (string.IsNullOrWhiteSpace(channelId))
+            return Task.CompletedTask;
+
+        _socket.SendRaw($"RTC_JOIN_CHANNEL|{_username}|{channelId}");
+        return Task.CompletedTask;
+    }
+
+    public void LeaveRtcChannel()
+    {
+        var channelId = _getCurrentChannelId();
+
+        if (string.IsNullOrWhiteSpace(channelId))
+            return;
+
+        _socket.SendRaw($"RTC_LEAVE_CHANNEL|{_username}|{channelId}");
+    }
+
+    public void SendRtcSignal(string json)
+    {
+        if (string.IsNullOrWhiteSpace(_socket.ServerPublicKey))
+        {
+            _sendRawToWebView("SendRtcSignal failed: server public key not loaded.");
+            return;
+        }
+
+        RtcSignalMessage? rtcSignal;
+
+        try
+        {
+            rtcSignal = JsonSerializer.Deserialize<RtcSignalMessage>(json);
+        }
+        catch (Exception ex)
+        {
+            _sendRawToWebView("SendRtcSignal failed to parse RTC signal: " + ex.Message);
+            return;
+        }
+
+        if (rtcSignal is null)
+            return;
+
+        rtcSignal.ChannelId ??= _getCurrentChannelId();
+        rtcSignal.From ??= _username;
+
+        if (string.IsNullOrWhiteSpace(rtcSignal.ChannelId))
+        {
+            _sendRawToWebView("SendRtcSignal failed: missing channel id.");
+            return;
+        }
+
+        var outgoingJson = JsonSerializer.Serialize(rtcSignal);
+
+        try
+        {
+            var encrypted = E2EeHelper.EncryptForRecipient(outgoingJson, _socket.ServerPublicKey);
+
+            var payload = new SocketRtcSignalMessage
+            {
+                Type = SignalType.EncryptedSignal,
+                SenderUsername = _username,
+                ChannelId = rtcSignal.ChannelId,
+                CipherText = encrypted.CipherText,
+                Nonce = encrypted.Nonce,
+                Tag = encrypted.Tag,
+                EncryptedKey = encrypted.EncryptedKey
+            };
+
+            _socket.SendJson(payload);
+
+            _sendRawToWebView($"SendRtcSignal sent: {rtcSignal.Type} -> {rtcSignal.To}");
+        }
+        catch (Exception ex)
+        {
+            _sendRawToWebView("SendRtcSignal failed: " + ex.Message);
+        }
+    }
+
+    public async Task<string> GetRtcParticipants()
+    {
+        var channelId = _getCurrentChannelId();
+
+        if (string.IsNullOrWhiteSpace(channelId))
+            return "[]";
+
+        var participants = await ServerAPI.GetRtcParticipantsAsync(channelId);
+        return JsonSerializer.Serialize(participants ?? []);
+    }
+
+    public async Task HandleIncomingRtcSignalAsync(SocketRtcSignalMessage payload)
+    {
+        var currentChannelId = _getCurrentChannelId();
+
+        if (payload.ChannelId != currentChannelId)
+            return;
+
+        if (payload.SenderUsername == _username)
+            return;
+
+        string decryptedJson;
+
+        try
+        {
+            var privateKey = KeyStorage.LoadPrivateKey(_username);
+
+            decryptedJson = E2EeHelper.DecryptForRecipient(
+                new EncryptedPayload
+                {
+                    CipherText = payload.CipherText,
+                    Nonce = payload.Nonce,
+                    Tag = payload.Tag,
+                    EncryptedKey = payload.EncryptedKey
+                },
+                privateKey
+            );
+        }
+        catch (Exception ex)
+        {
+            _sendRawToWebView("RTC decrypt failed: " + ex.Message);
+            return;
+        }
+
+        RtcSignalMessage? rtcSignal;
+
+        try
+        {
+            rtcSignal = JsonSerializer.Deserialize<RtcSignalMessage>(decryptedJson);
+        }
+        catch (Exception ex)
+        {
+            _sendRawToWebView("RTC signal parse failed: " + ex.Message);
+            return;
+        }
+
+        if (rtcSignal is null)
+            return;
+
+        if (!string.IsNullOrWhiteSpace(rtcSignal.To) &&
+            !string.Equals(rtcSignal.To, _username, StringComparison.OrdinalIgnoreCase))
+        {
+            _sendRawToWebView($"Ignoring RTC signal meant for {rtcSignal.To}");
+            return;
+        }
+
+        _sendRawToWebView("Received encrypted RTC signal: " + decryptedJson);
+
+        await SendRtcSignalToJsAsync(decryptedJson);
+    }
+
+    public Task PushRtcContextToJsAsync()
+    {
+        MainThread.BeginInvokeOnMainThread(async () =>
+        {
+            var usernameJson = JsonSerializer.Serialize(_username);
+            var channelIdJson = JsonSerializer.Serialize(_getCurrentChannelId());
+
+            await _hybridWebView.EvaluateJavaScriptAsync($"window.setUsername({usernameJson})");
+            await _hybridWebView.EvaluateJavaScriptAsync($"window.setChannelId({channelIdJson})");
+        });
+
+        return Task.CompletedTask;
+    }
+
+    private Task SendRtcSignalToJsAsync(string rawJson)
+    {
+        MainThread.BeginInvokeOnMainThread(async () =>
+        {
+            try
+            {
+                var jsArg = JsonSerializer.Serialize(rawJson);
+
+                await _hybridWebView.EvaluateJavaScriptAsync($@"
+                    try {{
+                        window.HybridWebView.SendRawMessage('C# eval entered');
+
+                        if (!window.RelaySocket) {{
+                            window.HybridWebView.SendRawMessage('window.RelaySocket missing');
+                        }} else if (typeof window.RelaySocket.receiveRtcSignal !== 'function') {{
+                            window.HybridWebView.SendRawMessage('RelaySocket.receiveRtcSignal missing');
+                        }} else {{
+                            window.HybridWebView.SendRawMessage('Calling RelaySocket.receiveRtcSignal');
+                            window.RelaySocket.receiveRtcSignal({jsArg});
+                        }}
+                    }} catch (err) {{
+                        window.HybridWebView.SendRawMessage('RTC JS dispatch failed: ' + err);
+                    }}
+                ");
+            }
+            catch (Exception ex)
+            {
+                _sendRawToWebView("SendRtcSignalToJsAsync failed: " + ex.Message);
+            }
+        });
+
+        return Task.CompletedTask;
+    }
+}

RelayServer/Services/Chat/ChatSocketBehavior.cs

@@ -6,7 +6,7 @@ using RelayServer.Services.Rtc;
 using WebSocketSharp;
 using WebSocketSharp.Server;
 using ErrorEventArgs = WebSocketSharp.ErrorEventArgs;
-using RelayShared.Rtc;
+using RelayShared.Services;
 
 namespace RelayServer.Services.Chat;